Supernumerary Digit Clinical Presentation

Updated: Aug 20, 2020
  • Author: Luke Lennox, MD; Chief Editor: Dirk M Elston, MD  more...
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Polydactyly is the most common congenital digital anomaly of the hand and foot. It may appear in isolation or in association with other birth defects. [9]


Physical Examination

Temtamy and McKusick [10] classified polydactyly into preaxial, central, and postaxial types. Preaxial polydactyly refers to the duplication of the first digit. Central polydactyly involves duplication of the second, third, or fourth digit. Postaxial polydactyly involves the fifth digit. The terms radial, central, and ulnar can be used to describe polydactyly in the upper extremity. Similarly, the terms tibial, central, and fibular can be used to describe polydactyly in the lower extremity.

The association of hand and foot polydactyly is uncommon. If hand and foot polydactyly does occur, it may be a case of "crossed polydactyly"—when preaxial involement of the hand and postaxial involvement of the foot occurs or vice versa.

Synpolydactyly is the combination of syndactyly and polydactyly. [11, 12]